Tuesday, January 6, 2009

SMC mod for single cable end stop sensors

Here's a picture of my modification to use a single RJ-45 cable for the minimum and maximum end stop sensors.

It allows the use of the unused orange wire(pin 2) to carry the opposite signal sense. As you can see from the picture I made use of the signal pad for maximum and soldered it to pin two of the RJ-45 jack.

From ExMrClean

While you are at it might make since to do the same going the other way so if you want to reverse your axis direction you would simply move the plug from the minimum jack to the maximum jack and turn around the motor plug on the other side of the board.

Also a quick picture of the 7404 inverter chip that I inserted/hacked inline to reverse the logic level from my hall effect sensors so that it matched the optical end stop polarity.

From ExMrClean

1 comment:

  1. Hey, is the final result of that inverter a normally low or high signal? I like the idea of a loose wire causing a machine fault. There's a "sensors inverting" flag in the Gcode interpreter firmware as well, so you can have it either way I believe.